1. Field of the Invention
The present invention relates to an intake passage structure for an internal combustion engine, and to an engine and a vehicle incorporating the same. More particularly, the present invention relates to an intake passage structure, in which an injector is oriented towards an intake valve of a cylinder head of an engine such that the injector does not interfere with an intake passage and a throttle body of the intake passage structure, and to an engine and a vehicle incorporating the same.
2. Description of the Background Art
There is a known internal combustion engine, in which an intake manifold is formed integrally with a cylinder head, and when viewed in a side view, an intake passage formed continuous with the intake manifold is extended parallel to a cylinder central axis. An example of such internal combustion engine is disclosed in the Japanese Patent Laid-Open No. Hei 11-82157.
In an internal combustion engine equipped with an injector (fuel injection valve) for supplying fuel into a combustion chamber, it is necessary that the injector is arranged with a leading end thereof oriented towards a direction of an intake valve. Therefore, in many cases, the injector is usually provided in the intake manifold. In an internal combustion engine configured such that the intake passage extends parallel to the cylinder central axis, as in the conventional art, the injector may be attached to the intake passage while keeping such an orientation of the injector.
In such cases, the injector is inevitably tilted to come close to the intake passage. This leads to a problem of the injector interfering with the intake passage, or with a throttle body and a connection pipe connected to the intake passage. Accordingly, it is necessary that the injector is disposed at an appropriate location in the engine while preventing interference thereof with such peripheral components.
The present invention has been made to overcome such drawbacks of existing disposition of an injector in an internal combustion engine. Accordingly, it is one of the objects of the present invention to dispose an injector so that a leading end thereof is oriented towards a direction of an intake valve while preventing interference with peripheral components.